Characteristics And Source Apportionment Of PM_2.5 Components In Different Pollution Levels Of Autumn And Winter In Jinan

To understand the pollution characteristics and cause of fine particulate matterin in different pollution levels of Autumn and Winter in Jinan,PM2.5 samples were collected at Jinan in October 2017 to January 2018.The mass concentration and component composition of PM2 5(inorganic elements,carbonaceouss pecies and water-soluble ions)were analyzed in the city(Environmental Monitoring Station,Jianzhu university,Jigang and Lanxiang Technical School)and Paomaling Station(background point).The lain conclusions were as follows:the average mass concentration of PM2.5 collected by hand,NO3-,SO42-and NH4+ in city during serious pollution was 5.50,7.10,12.26 and 8.08 times higher than on clear days,and 4.00,4.24,3.90 and 4.12 times higher than on clear days in the Paomaling Station.The ratio of NO3-/SO42-greater than 1 of good days,light pollution days,moderate pollution days and heavy pollution days in city and Paomaling,which indicated that pollutants mainly came from mobile sources,especially traffic emissions.(2)The mass concentration of OC and EC in city and Paomaling during serious pollution was 3.20,3.20 and 2.84,5.72 times higher than on clear days.There were secondary organic carbon in city(the average daily concentration of SOC on light pollution,moderate pollution and heavy pollution days was 2.98,4.09;and 5.84μg/m3)and Paomaling(the average daily concentration of SOC on clear,light pollution,moderate pollution days was 2.52,4.60 and 5.70μg/m3).(3)The results of CMB showed that main sources in city were secondary nitrate and secondary sulfate,the contribution rate was 23.4%-32.4%and 11.9%-19.1%,respectively.Fugitivedust and vehicle emissions were the third and fourth major contributors,contribution rate were 7.4%-17.2%and 7.6%-8.8%;the fifth largest source was biomass burning with a rate of 4.7%-7.1%.Ironmaking,construction dust,soil dust and SOC contribute less to PM2.5 secondary nitrate and secondary sulfate were the first and second major contributors in Paomaling.The sharing rates were 34.5%-36.1%and 16.6%-19.9%respectively.Dust and SOC were the third and fourth major contributors,with a range of 7.4%-16.1%and 5.3%-6.2%,other sources contributed less.